Effects of Bilateral Transcutaneous Tibial Nerve Stimulation on Neurogenic Detrusor Overactivity in Spinal Cord Injury: A Urodynamic Study.

Abstract

To study the short-term effect of bilateral transcutaneous tibial nerve stimulation (TTNS) on urodynamic study (UDM) parameters in spinal cord injury (SCI) patients with neurogenic detrusor overactivity (NDO). Single-blinded sham-controlled study. Rehabilitation center. SCI patients with NDO (N=17) were recruited. Fifteen patients (mean age, 40±18y) completed the study. Most of the patients had chronic incomplete SCI. UDM was performed 3 times. The first UDM was performed after taking anticholinergics for 1 hour to assess the effects of medication. After stopping anticholinergics for a 5 half-lives, the second UDM was performed immediately after a 20-minute sham TTNS (switch on for 30s at the beginning, switch off for 20min, and switch on for 30s before stopping). The third UDM was performed immediately after a 20-minute bilateral TTNS. Reflex volume (mL), cystometric capacity (mL), maximum pressure detrusor (mmH₂O), and bladder compliance (mL/mmH₂O). UDM tracings were interpreted by 2 blinded assessors. This study used per-protocol analysis and repeated measures Analysis of variance with Bonferroni post hoc analysis. When compared with sham stimulation, bilateral TTNS and anticholinergics produced greater increases in reflex volume (136.1±99.88, 212.2±112.82, and 226.3±111.52 mL; P<.001), cystometric capacity (218.3±137.66, 319.1±143.74, and 350.7±163.43 mL; P<.001), and compliance (5.8±6.81, 7.9±6.74, 9.7±8.12 mL/cmH₂O; P=.02). No significant differences were found in reflex volume, cystometric capacity, or compliance between bilateral TTNS and anticholinergics (P>.05). The maximum pressure detrusor was not significantly different between groups (P>.05). Bilateral TTNS may be an effective short-term intervention to improve UDM parameters in SCI with NDO. Further study is necessary to determine the long-term effects and benefits of combined bilateral TTNS with anticholinergics.